diff --git a/DDDigi/io/DigiIO.h b/DDDigi/io/DigiIO.h
index 58d7bcf1fd170c52683a446fdefde64e094aed9b..a8eff62e957fb48be3b79dcdff073993f7b67437 100644
--- a/DDDigi/io/DigiIO.h
+++ b/DDDigi/io/DigiIO.h
@@ -76,7 +76,10 @@ namespace dd4hep {
       void _to_edm4hep(const FIRST& first, SECOND& second, int hit_type);
 
       template <typename FIRST, typename SECOND> static
-      void _to_edm4hep(const FIRST& cont, SECOND coll, int hit_type);
+      void _to_edm4hep(const FIRST& first, SECOND& second, int hit_type);
+
+      template <typename FIRST, typename SECOND, typename THIRD> static
+      void _to_edm4hep(const FIRST& first, const SECOND& second, THIRD& third, int hit_type);
 
       template <typename FIRST, typename SECOND, typename THIRD> static
       void _to_edm4hep(const FIRST& first, const SECOND& second, THIRD& third, int hit_type);